The following patent publications and commercially available products are believed to represent the current state of the art:
U.S. Pat. Nos. 3,837,347; 4,040,413; 4,148,307; 4,176,662; 4,195,637; 4,261,339; 4,453,545; 4,616,652; 4,676,228; 4,862,874; 4,917,088; 5,135,487; 5,259,366; 5,593,419; 6,007,482; 6,461,294; 6,585,639; 6,663,589; and 6,702,735;
U.S. Patent Application publication Nos. 2003/0244361; 2004/0102681; 2005/0124856; 2005/0125005; 2005/0133453; 2005/0137457; 2005/0165233; 2005/0165273; 2005/0171400; 2006/0111610; and 2006/0161044;
Japanese Patent Application publication No. JP2003-250896;
Published PCT Patent Applications WO 2005/074377; WO 2005/017854; WO 2007/135665; WO 2008/004228; WO 2008/142685; WO 2009/122395; WO 2010/046891; WO 2010/137025; WO 2011/111040; and
Double Balloon Endoscope product, including EC-450BI5 colonoscope, TS-13101 overtube and BS-2 front balloon, which interface with balloon pump controller BP-20 and EPX-4400HD video system, all commercially available from Fujinon Inc., of 10 High Point Drive, Wayne, N.J., USA.